The present disclosure relates generally to a magneto-dielectric substrate useful in applications such as metal clad circuit materials for circuits, antennas, and the like.
Newer designs and manufacturing techniques have driven electronic components to increasingly smaller dimensions, for example, components such as inductors on electronic integrated circuit chips, electronic circuits, electronic packages, modules and housings, UHF, VHF, and microwave antennas. One approach to reducing electronic component size has been the use of magneto-dielectric materials as substrates. In particular, ferrites, ferroelectrics, and multiferroics have been widely studied as functional materials with enhanced microwave properties. However, these materials are not entirely satisfactory, in that they may not provide the desired bandwidth or have the desired mechanical performance for a given application. Developing materials with sufficient flame retardancy has been particularly difficult because the particulate metallic fillers used to impart the desired magneto-dielectric properties are combustible. Such fillers are also not stable under high humidity conditions, even when surrounded by the polymeric matrix.
There accordingly remains a need in the art for magneto-dielectric materials for use in dielectric substrates having optimal magnetic and dielectric properties at frequencies greater than 100 megaHertz (MHz), while at the same time having optimal thermomechanical and electrical properties for circuit fabrication. In particular, there remains a need for magneto-dielectric substrates with one or more of low dielectric and magnetic losses, low power consumption, low biasing electric or magnetic fields, flame retardance, and other improved mechanical properties. It would be a further advantage if the materials were easily processable and integratable with existing fabrication processes. It would be a still further advantage if the thermomechanical and electrical properties were stable over the lifetime of the substrates under conditions of heat and humidity.